1. Field of the Invention
The present invention relates to a swirl chamber type Diesel engine and more particularly to an ignition timing sensor for a swirl chamber type Diesel engine.
2. Description of the Prior Art
An ignition timing sensor detects the ignition timing of a Diesel engine from combustion light in a swirl chamber. To prevent the input end of the ignition timing sensor from being covered with deposits due to the combustion of fuel containing a large amount of sulfur(S) the ignition timing sensor is separated from the glow plug, the glow portion of which is in a location directly contacting the injection fuel. The ignition timing sensor is mounted on the opposite side of the glow plug with respect to the fuel injection nozzle, i.e., where the injection fuel from the fuel injection nozzle will not contact directly said sensor. In the prior art Diesel engines, however, the input end of the ignition timing sensor projects from the wall surface of the swirl chamber. In such Diesel engines using low octane number fuel and having EGR (Exhaust Gas Recirculation), deposits may be formed gradually on the input end and reduce the luminous intensity detected by the ignition timing sensor with the passage of time.